Electric secondary clock.



H. B. MOGABB.

ELECTRIC SECONDARY CLOCK. APPIIJIGATION FILED NOV. 12, 1000.

. Patented Nov. 17, 1908.

UNITED STATES PATENT orricn.

HORACE B. McOABE, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO JOSEPHF. GOCHRAN,

OF CHICAGO, ILLINOIS.

ELECTRIC SECONDARY oLooK.

Specification of Letters Patent.

Patented Nov. 17, 1908 Application filed November 12, -19t)6. Serial No.342,933.

Illinois, have invented certain new and useful Improvements in. ElectricSec'ondam Clocks, of'which the following is a full, clear, and exactspecification.

Theinvention relates to improved mechanism for operating electric clocksand particularly to what are known as secondary clocks which areconnected in a circuit controlled by a primary clock. I

The primary object of the invention isv to provide "an ii'nprovedratchet mechanism adapted to transform the reciprocatingor vibratingmovement of an armature into the rotarv movement required to drive theclock hands. which is simple, cheap and absolutely accurate in itsoperation.

To the attanimentof these ends andthe accomphsln'nent of other new anduseful objects, as will appear, the invention consists in the featuresof novelty in the construction, combination and arrangement ofthevarious .parts, hereinafter more fully described and claimed and shownin the accompanying drawings, illustrating an exemplificatio'n of thisinventiomand in'whicl1:.-

Figure 1 is rear elevation of a clock movement embodying the invention,the limits of movement of the operative parts being shown in dottedlines. .Fig. 2 is a broken detail view ofthe pawl which engagesthe teethon the ratchet wheel. Fig. 3 is a broken plan view of the lowersupporting frame work, This view shows the means employed in pivotingthemember to which the armature is attached, Theview} also shows the metalcore of the magnet adjacent to the pivoted member in :horiZontalsection, as

well as horizontal section of the upright arm on the pivoted member towhlch the driving pawl is attached. Fig. d is a vertical sectional viewon line 44, Fig. 3.- Figs. 5 and (3 are modified views of driving pawlsand modified views of their cooperating locking members.

In clocks of this character it is customary to provide a number of themin a single circuitcontrolled by means of one primary clock. The commonmanner of operating the secondary clocks is-to provide mechanism wherebythe primarycloek closes the circuit at convei'iient intervals. In thepresent device provision is made for the operation of the mechanism insecondary clock at intervals of one minute. The ratchet wheel 1 isjournalcd on a rotating shaft designed to. carry the minute hand. v

2 is the main frame provided with convenient means, as for example,screw holes L, for attachment to, the clock casing.

3 is an upright support attached to frame 2. and serves as'one of thesupports for sustaining the journal on which ratchet wheel 1 is mounted.I v 4 and5 are common form of electro magnets supported on frame 2 byhaving their metal cores and 5 extending into frame 2 (see Figs. l and3). hen the primary clock closes the circuit magnets l and 5 becomeenergized and attract armature 6 which is pivotally mounted adjacent tothe lower ends of the magnet cores 4 ando Frame 2 is provided withbranch members 2 and 2 for holding adjustable pivots 7 and 8. Ar mature6 is adjustably secured to member 9 which is mounted to rock on pivots 7and 8.. Pivots 7 andS maybe adjustably secured in and '15. Pivotedrocking member 9 is provided with an upwardly. extending arm.9

moves in the direction indicated by the. ar- Y row and it Will'be notedthat teeth 11 are so inclined to the circumference of the wheel that thedriving ratchet is effective to'move them only in the diiectionindicated by the arrow. The driving pawl 10 is provided with suitablemeans, as branch 10, for taking into teeth 11 and this pawl is allowedto rest normally. on top of'the wheel in contact with the teeth withwhich it is held in constant engagement by gravity.

' By referring to Fig. 1 it will be seen that the position of thearmature indicated by full lines is out of contact with the magnet.IVhen thecir'cuit is closed by the primary clock and the magnetenergized the armature is thrown upwardly into contact witlrthe 80 frame2 by means of suitable set screws 14 i magnet cores which rocks member 9and upwardly extending arm 9 in the manner indicated in dotted lines.will be seen, causesthe withdrawal of driving pawl which movement of thepawl is in the direction opposite to the movement of wheel 1 asindicated by the arrow. Ar-

- mature 6 is provided with the weight memher 6 'which containssufficient material to cause the armature to move downwardly away fromthe magnet cores when the current is broken by the primary clock. The

downward movement of armature 6 it will be seen again restores member 9and upright member 9 to normal position as indicated in theillustration, which movement also operates driving pawl 10 which, inturn, 1n engaging with one of the teeth 11 causes wheel 1 to rotate inthe direction ofthe arrow one space or the distance between two of theadjacent teeth. In order that the movement of pawl 10 may be adjusted inrelation to armaturee provision is made for varying the relation betweenarmature 6 and pivoted member 9 and member 9 is provided on the lowersurface with the small. depend-,'

ing lug or support 9 and the adjustable support 12. The member 12 isscrew threaded into member 9. 6 is held in contact with 9"- and 12 bymeans ofsuitable adjusting screw as 13 passing therethrough and threadedinto member In order that the armature 6.may not become too widelyseparated from the magnet pole 4" pole contact member 16 having angularbranch 16' is provided and the outer end of armature 6 is depressed atan angle to correspond with the angular branch 16*. The member 6 whichis attached to weight (l may also be employed in order that the armaturemay be provided with a surface to correspond with the surface of polemember 1 16 and to keep the armature from direct co ntact with ma etcores. This arrangement of the parts, it will be seen, causes members 16and 6 to move more or less longitudinally with reference to each otherwhen the ari-natureis rocked which enables them to retain about the samelateral distance be-- tween each other as do the armature 6 an the pole5 In a clock movement of this character the minute hand, which iscarried directly by shaft supporting ratchet wheel 1 is ordinarily ofmetal and several inches in length. To overcome this weight it is commonto put a counter balance on wheel 1 or to extend the minute handrearward of its point of attachment to the shaft andplacethe'counterweight thereon. This adds weight to the parts, and one of thedifliculties heretofore experienced has been due to the fact that theinertia of the mechanism when moved a space by the driving pawl has badThis movement, it

a tendency to overrun or move more than a single space at each closingof the circuit.

Excessive jarring of the movements of such clocks, due to vibrations ofbuildings, may in some cases also cause the movementto overrun when thehands are in certain favorable positions. Such jars or vibrationsimparted to the movement may also cause the mechanism to be carried inthe opposite di-- rection. To prevent the possibility of any suchinaccuracies in the. movement the and the auxiliary ratchet' stop l9 areprogravity pawl 17, the driving pawl lock 18 r vided. The upright member20, supporting pawl 17 and angular locking surface 18 may beconveniently attached to upright member '80 long as the armature remainsin its de-' pressed position and that this position of the pawl willlock the wheel 1 against further advance motion until the movement ofthe armature releases the pawl by withdrawing it. When thecircuit isclosed and the driving pawl 10 is withdrawn in the manner heretoforedescribed it will be seen that'the locking efiect of pawl 10 is releasedand during the interval between the withdrawal of the pawl and thebreaking of the circuit the wheel 1 will again be free to rotate in aforward direction. To supply an auxiliary lock during this interval themember 19 is provided. This member may be attached to upright arm 9? orto any of the parts operated by the armature and should be so positionedthat when driving pawl 10- is in looking position the engaging end oflock the mechanism has withdrawn pawl 10 from locking position auxiliarylock 19 should be brought into operative position which will cause it tocontact with the periphery of the wheel between two adjacent teeth;

In Figs. 5 and 6 modifications of driving pawl 10 are shown, alsomodifications in construction and arrangement of mechanism for 19 shouldnot contact with teeth ll but when locking the driving pawl in thenormal position to prevent overrunning of ratchet wheel,

as above described. In Fig. 5 driving pawl is designated by numeral 21,the locking member by 22 and its beveled engaging sur-' face by 23. InFig. 6 pawl 21 is of the same formas shown in Fig. 5. 21 is shown inconjunction with a locking member of cylindrical form which may be a pinor rod supported in any desired manner.

In order that the invention might be fully the combination with atoothed wheel and its reciprocating actuating pawl, said actuating pawlbeing provided withanQengaging end projecting transversely outside theplane of ber for the-actuating pawl having an engaging surface outsideof the'plaue of the wheel.

.3. In a device of the character described, the combination with aframe, of magnetic cores mounted thereon, a yoke joining said cores atone end thereof, a movable armature at the other end of said cores, ashaft journaled in said frame and disposed transversely between saidyoke and said armature, and means for transmittin the movement of saidarmature to said sha t.'

4. In a device of the character described, the con'ihinatiou with aframe, of an electro magnet having cores passing through said frame,coils on said cores on one side of the said frame, a movable armature inthe magnetic field of'the cores on the reverse side of said frame, anupwardly extending branch on said frame, anarbor or shaft carrying atoothed wheel journaled therein, a pawl in engagement with the wheel,and means for actuating the pawl from the said armature.

5. In a device of the character described, the combination with a mainframe, of an electro-magnet secured to the main frame, an upright branchonthe main frame, a toothed 'wheel carried thereby, a verticallyextending rocking member pivotally secured to the main frame at itslower extremity, a pawl carried near the upper extremity thereof andhaving an engaging portion in contact with said toothed wheel, anarmature cooperating with the said electro-maguet and adj-ustablysecured to the pivotedrocking member at the lower extremity thereof, amember secured I to the upper extremity of the said upright branch andprovided with an angular surface adapted to cooperate with the pawl onthe said pivoted rockin member and a gravity pawl carried by t e memberon the upright branch and adapted to prevent a reverse movement of thetoothed wheel.

.6. In a device of the character described, the combination with'a mainframe, of an electro-magnet secured to the main frame, an uprightbranchon the mainframe, a toothed wheel carried thereby, a verticallyextending rocking member pivotally secured to the main frame at itslower extremity, a pawl carried near the upper extremity thereof andhaving an engaging portionin contact with said toothed wheel, and anarmature cooperating with the said electro-magnet and adjustably securedto the said pivoted rocking member at the lower extremity thereof.

7. In a device of the character described, the combination of a toothedwheel, a pivoted member, a driving pawl carried by said pivoted memberand adapted to'engage said toothed wheel, engaging means adapted toforce said pawl into contact with said toothed wheel, and auxiliarylocking means mounted on said pivoted member and adapted to contact withsaid toothed wheel when said driving pawl has been withdrawn from itsengaging means bysaid pivoted member.

. 8. In a device of the character described,

the combination with a frame, an electromagnet mounted thereon, apivoted member, an armature secured thereto and extendmg into the fieldof the said magnet, and means

